The invention relates to a process for assembling two facing extremities of members, and more specifically to such a process wherein the extremities are assembled by means of two half-shells joined by assembly components, and to a detachable link embodied by means of this process.
Detachable links are known comprising mortise and tenon joints, which are used to join sections of anchor chains for ships or oil drilling platforms.
In another known type of detachable link, two halves of the links are assembled and held together by means of two shells fastened with bolts, wherein the shells display ridges which cooperate with projections formed at the free ends of the link halves.
To provide adequate strength for the two aforesaid types of links, a great deal of care and precision is required in machining the parts that come into contact with one another, so as to minimize the amount of play in the assembly and to provide good tensile and fatigue strength. The cost of these numerous precision machining operations is relatively high.
An object of this invention is an assembly process and a detachable link implemented by means of this process requiring almost no machining of the contacting parts, and therefore costing much less than known processes and links.
To this effect, a first object of the invention is a process for assembling the two facing extremities of members by means of two half-shells joined together by assembly components such as bolts, characterized in that it comprises the following steps:
reliefs are formed either on the inside surface of the half-shells, or on the outside surface of the member extremities; PA1 the half-shells are mounted on the member extremities; PA1 reliefs are forged on the initially smooth components by direct stamping onto the components displaying the reliefs; PA1 the two half-shells are joined by means of the said assembly components. PA1 reliefs are formed either on the inside surface of the half-shells, or on the outside surface of the extremities of the link members; PA1 a hole is drilled in each half shell, through the parts which are designed to face one another; PA1 two complementary assembly components are formed, each having an extremity designed to penetrate into one of the said holes; PA1 reliefs are formed either on the inside surface of the said holes, or on the outside surface of the extremities of the assembly components; PA1 each of the said extremities of the assembly components is inserted into one of the said holes and the half-shells are mounted on the extremities of the link members; PA1 reliefs are forged on the initially smooth parts facing the reliefs that are preformed by direct stamping on the said reliefs; PA1 the two half-shells are joined by means of an assembly pin inserted through two aligned holes formed in the overlapping parts of the two halves of the assembly components.
The expression "initially smooth" as used in this specification and in the accompanying claims means that the surface of these components has not been subjected to any machining whatsoever. On the other hand, they may be preformed by forging.
Therefore, the reliefs are formed initially on only one contact surface, and the corresponding reliefs on the other surface are formed directly by stamping from these initial reliefs. This ensures that there will be no play in the resulting assembly, thereby providing improved tensile and fatigue strength.
Moreover, it has been observed that although they are produced without machining, the reliefs formed by stamping onto the initially smooth surface are of good quality, and that reassembling the members after they have been disassembled does not present any particular problem.
In one particular embodiment, the reliefs are formed initially on the extremities of the members and the inside surfaces of the half-shells are smooth or merely initially preformed and then the reliefs in the half-shells are forged by stamping.
A further object of the invention is a detachable link for assembling and disassembling chain segments. This detachable link comprises at least two facing extremities of link members and two half-shells joined together by assembly components for assembling the said extremities, wherein the extremities of these link members are joined by the process described hereinabove.
In addition to the aforesaid advantages, the links according to the invention may be thinner for a given cross-section because of improved stress distribution and due to the fact that the metal fibers are not damaged by machine tools. Moreover, these links may readily be assembled and disassembled on site.
In a first embodiment, the said links are formed of two half-links with two pairs of facing extremities, and the two half-links are assembled by two half-shells so as to form a bridge over the gap in the link.
In a further embodiment, the said links are formed by an open ring, the two facing extremities of which are joined by two half-shells.
More particularly, each half-shell may comprise a projection which protrudes toward the other half-shell, these two projections being complementary, both being traversed by an assembly pin. Each projection is formed by a component inserted in a hole drilled in its respective half-shell and held in place in this hole by forging.
Advantageously, either the outside surface of the projecting member or the inside surface of the hole comprises reliefs which are stamped onto the other surface at the time of forging.
A still further object of the invention is a process of fabricating a detachable link for assembling and disassembling chain segments, wherein the said link comprises at least two facing extremities of link members and two half-shells joined together by assembly components for assembling the said extremities, characterized in that it comprises the following steps:
The said aligned holes may be drilled after forging from the outside of the link.
They may also be drilled before forging and may be used to join temporarily the two halves of the assembly components.
In one particular embodiment of this process, intended for the fabrication of a link consisting of two half-links comprising two pairs of facing extremities, reliefs are formed either on the inside surface of a sheath, or on the outside surface of the extremities of the other pair of extremities, the said other extremities are inserted in the sleeve, and these other extremities are forged simultaneously with the aforesaid first extremities.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.